1. Field of the Invention
This invention pertains to the art of reclosable plastic bags having extruded zippers, and more particularly to a reclosable bag having fastener profiles having wedge-shaped stops, which facilitate the joining attachment of the fastener profiles and which determine the amount of pull force required to open the bags. The fastener profiles are further of a design which makes inadvertent opening of the bags less likely.
2. Description of the Prior Art
Reclosable bags used, for example, for storing household foodstuffs are typically made of polyethylene. As shown in U.S. Pat. No. 3,416,199 to Imamura commonly assigned with the present invention, a reclosable bag may be formed of two opposed walls equipped at the mouth with fastener profiles. These profiles include a male profile attached to one wall and a female profile on the other wall. The profiles are shaped so that, when they are aligned and pressed together into an engaging relationship, they form a continuous closure for the bag. The bag may be opened by pulling the walls apart thereby separating the profiles. Various geometric shapes and arrangements for such profiles are shown in U.S. Pat. Nos. 28,969; 3,323,707; 4,212,337; 4,363,345; 4,561,108; and 4,812,056. In addition, U.S. Pat. Nos. 4,736,496 and 5,012,561 disclose reclosable bags with profiles and internal ribs adjacent to the profiles. U.S. Pat. No. 4,822,539 discloses a reclosable bag with interlocking profiles, internal guiding ribs disposed adjacent to the profiles, and stabilizing beams disposed on the outside surface of the bag wall. U.S. Pat. No. 3,338,285 discloses a reclosable bag having several parallel interlocking male and female profiles. In general, the profiles must be such as to provide relatively high resistance to opening from inside the bag while rendering the bag relatively easy to open from the outside.